1. Field of the Invention
The present invention relates to an IC measuring mechanism. In particular, the present invention relates to an IC measuring mechanism, provided in a horizontal carrier-type auto-handling device, which reduces the mechanical stress on the IC lead at the time of inserting the IC lead into an IC socket for measuring and conducting testing thereof.
2. Background Art
In the following, the construction of a conventional IC measuring mechanism will be explained based on FIG. 2. FIG. 2 is a cross-sectional diagram showing a depressing member 2, elastic member which forms a compression coil spring 3, IC socket 4, vacuum generating means 6 which forms a vacuum generator, heating member 7, IC 10 and hand 21.
In FIG. 2, hand 21 is formed by means of depressing member 2, compression coil spring 3 (herein after referred to as just "spring"), and heating member 7. A shaft 7D is provided in the upper portion of heating member 7 which is connected in a slidable manner with depressing member 2. Spring 3, which is installed between depressing member 2 and heating member 7, has the power to move depressing member 2 and heating member 7 in opposite directions.
As shown in FIG. 2, IC 10 is loaded onto IC socket 4 which forms an electrode. Suction aperture 7C is provided in the bottom surface 7A of heating member 7 by means of which suction of IC 10 is possible via linkage to vacuum generating means 6. In addition, a heater 7B is housed within heating member 7 for heating IC 10 by means of IC 10 depression by heating member 7 during measurement.
According to FIG. 2, hand 21 is pushed towards IC socket 4 by means of a lift mechanism (not shown in the figure), such that the lead of IC 10 comes into contact with the contact components 4A of IC socket 4 by means of depressing member 2, while heating member 7 is pressed against IC 10 via the elastic strength of spring 3. In this manner, a good heat conductance efficiency is obtained.
In the following, the action of hand 21 will be explained with reference to FIG.'s 3 and 4. FIG. 3 shows the suction action of IC 10 onto the top of the supply stage 13 by means of hand 21. According to FIG. 3, IC 10 is suctioned by means of lowering hand 21 such that the bottom surface 7A of heating member 7 contacts IC 10 and continues to move downward thereafter for another 1.about.2 mm. Spring 3 also functions to absorb some of the shock from the impact of heating member 7 striking IC 10.
FIG. 4 shows a state in which hand 21 is moving while maintaining suction onto IC 10. According to FIG. 4, heating member 7 is positioned at the lowest end of hand 21 by means of its intrinsic weight.
However, problems arise in that due to the intrinsic weight of heating member 7 and the elasticity of spring 3, bending of the lead often occurs especially when an IC possessing a lead comprising a poor hardness is used (in place of IC 10 in FIG. 2). Particularly, QFP-type and SOP-type IC's possess leads which have a tendency to wear and thin out with time, and hence require considerable attention.
Decreasing the spring 3 elastic strength has been proposed to counteract the aforementioned phenomenon, however, by decreasing the elastic strength of spring 3, for example in FIG. 2, when hand 21 is raised while maintaining suction onto IC 10 and then suddenly stopped, heating member 7 continues upward due to inertia resulting in the release (dropping) of the IC. In other words, during lifting of hand 21, an elastic strength is required of spring 3 which will permit only minute changes due to acceleration of heating member 7. Additionally, further problems associated with a reduction in the apparatus efficiency arise when attempting slow the speed of movement of hand 21.